CN-122026719-A - Booster and reference control circuit

Abstract

A booster includes a charge pump, a boost control circuit, a bandgap circuit, a voltage divider, and a reference control circuit. The charge pump generates a pump voltage based on an input supply voltage. The boost control circuit generates an adjustment signal for controlling the charge pump according to the charge pump reference voltage and a feedback voltage of the pump voltage. The bandgap circuit generates a bandgap voltage based on the pump voltage. The voltage divider generates an input power supply reference voltage according to an input power supply voltage. The reference control circuit generates a charge pump reference voltage from an input power supply reference voltage before the bandgap circuit is ready, and generates a charge pump reference voltage from a bandgap reference voltage derived from the bandgap voltage after the bandgap circuit is ready.

Inventors

• ZHANG JIAFU
• LI JIAQING

Assignees

• 力旺电子股份有限公司

Dates

Publication Date

20260512

Application Date

20251107

Priority Date

20241112

Claims (19)

1. 1. A booster, comprising: A charge pump configured to generate a pump voltage from an input power supply voltage; a boost control circuit configured to generate an adjustment signal to control the charge pump by comparing a charge pump reference voltage with a feedback voltage derived from the pump voltage; a bandgap circuit configured to generate a bandgap voltage from the pump voltage; a first voltage divider configured to generate an input power supply reference voltage from the input power supply voltage; And The reference control circuit includes an output configured to output the charge pump reference voltage in accordance with the input power supply reference voltage before the bandgap circuit is ready, and to output the charge pump reference voltage in accordance with a higher one of the input power supply reference voltage and a bandgap reference voltage derived from the bandgap voltage after the bandgap circuit is ready.
2. 2. The booster of claim 1, wherein the reference control circuit comprises: a first amplifier having a non-inverting input configured to receive the bandgap reference voltage, an inverting input, and an output coupled to the inverting input; a second amplifier having a non-inverting input coupled to the output of the first amplifier, an inverting input configured to receive the input power supply reference voltage, and an output, and A transistor having a first terminal configured to receive the input supply voltage, a second terminal coupled to the output terminal of the first amplifier, and a control terminal coupled to the output terminal of the second amplifier.
3. 3. The booster of claim 2, wherein the output of the first amplifier is the output of the reference control circuit.
4. 4. The booster of claim 2, wherein the transistor is a P-type transistor and is turned on by the second amplifier to boost the charge pump reference voltage when the bandgap reference voltage is lower than the input power reference voltage.
5. 5. The booster of claim 2, wherein the reference control circuit further comprises: A first switch having a first end configured to receive the input power supply reference voltage, a second end coupled to the output end of the reference control circuit, and a control end configured to receive a first control signal, and A second switch having a first terminal coupled to the output terminal of the first amplifier, a second terminal coupled to the output terminal of the reference control circuit, and a control terminal configured to receive a second control signal.
6. 6. The booster of claim 5, wherein the first control signal is configured to turn on the first switch during a set period before the bandgap circuit is ready, and the second control signal is configured to turn on the second switch after the set period.
7. 7. The booster of claim 1, wherein the reference control circuit comprises: An integrator having an input configured to receive the bandgap reference voltage, and an output; A first switch having a first end configured to receive the input power supply reference voltage, a second end coupled to the output end of the reference control circuit, and a control end configured to receive a first control signal, and A second switch having a first terminal coupled to the output terminal of the integrator, a second terminal coupled to the output terminal of the reference control circuit, and a control terminal configured to receive a second control signal.
8. 8. The booster of claim 7, wherein the first control signal is configured to turn on the first switch during a set period before the bandgap circuit is ready, and the second control signal is configured to turn on the second switch after the set period.
9. 9. The booster of claim 7, wherein the first control signal is configured to turn on the first switch during a set period before the bandgap circuit is ready, and the second control signal is configured to repeatedly turn on and off the second switch after the set period.
10. 10. The booster of claim 9, wherein after the set period, a duty cycle of the second control signal is less than 50%.
11. 11. The booster of claim 1, further comprising a second voltage divider configured to generate the feedback voltage based on the pump voltage.
12. 12. The booster of claim 1, wherein the boost control circuit includes a comparator configured to generate the adjustment signal to reduce the pump voltage when the feedback voltage is above the charge pump reference voltage and to boost the pump voltage when the feedback voltage is below the charge pump reference voltage.
13. 13. The booster of claim 1, wherein the reference control circuit includes a capacitor having a first end coupled to the output of the reference control circuit and a second end configured to receive a system reference voltage.
14. 14. The booster of claim 1, further comprising a low pass filter configured to filter the pump voltage before the bandgap circuit receives the pump voltage.
15. 15. A reference control circuit configured to provide a charge pump reference voltage to a charge pump to adjust the charge pump according to an input supply voltage to generate a pump voltage, the reference control circuit comprising: A first amplifier having a non-inverting input configured to receive a bandgap reference voltage, an inverting input, and an output coupled to the inverting input, wherein the bandgap reference voltage is generated from a bandgap voltage output by a bandgap circuit; a second amplifier having a non-inverting input coupled to the output of the first amplifier, an inverting input configured to receive an input power supply reference voltage generated from the input power supply voltage, and an output, and A transistor having a first terminal configured to receive the input supply voltage, a second terminal coupled to the output terminal of the first amplifier, and a control terminal coupled to the output terminal of the second amplifier.
16. 16. The reference control circuit of claim 15, wherein the output of the first amplifier is coupled to the output of the reference control circuit.
17. 17. The reference control circuit of claim 15, wherein the transistor is a P-type transistor and is turned on by the second amplifier to raise the charge pump reference voltage when the bandgap reference voltage is lower than the input power reference voltage.
18. 18. The reference control circuit of claim 15, wherein the reference control circuit further comprises: A first switch having a first end configured to receive the input power supply reference voltage, a second end coupled to the output end of the reference control circuit, and a control end configured to receive a first control signal, and A second switch having a first terminal coupled to the output terminal of the first amplifier, a second terminal coupled to the output terminal of the reference control circuit, and a control terminal configured to receive a second control signal.
19. 19. The reference control circuit of claim 18, wherein the first control signal is configured to turn on the first switch during a set period before the bandgap circuit is ready, and the second control signal is configured to turn on the second switch after the set period.

Description

Booster and reference control circuit Technical Field The present invention relates to a booster, and more particularly, to a booster for low power applications having a reference control circuit. Background To meet the demand for low power consumption of electronic devices, integrated circuits (INTEGRATED CIRCUIT, ICs) have been redesigned to be suitable for operation in low voltage environments. While lower voltages are advantageous for reducing power consumption, in some cases higher voltages are still required for operation of the circuit. In this case, a charge pump is typically used to provide the higher voltage. Generally, in order to dynamically adjust an output voltage and maintain it within a stable range, a charge pump needs to convert the output voltage into a feedback voltage and compare the feedback voltage with a reference voltage to implement a feedback mechanism. In this case, how to provide a stable reference voltage becomes a key issue for starting the charge pump and maintaining the stability of the charge pump. The background information is provided only in this "prior art" section. The statement of this "prior art" does not constitute an admission that the subject matter disclosed in this section constitutes prior art to the application, and any part of this "prior art" section is not to be taken as an admission that any part of the application (including this "prior art" section) constitutes prior art to the application. Disclosure of Invention One aspect of the present invention provides a booster. The booster includes a charge pump, a boost control circuit, a bandgap circuit, a voltage divider, and a reference control circuit. The charge pump generates a pump voltage based on an input supply voltage. The boost control circuit generates an adjustment signal to control the charge pump by comparing the charge pump reference voltage with a feedback voltage derived from the pump voltage. The bandgap circuit generates a bandgap voltage based on the pump voltage. The voltage divider generates an input power supply reference voltage according to an input power supply voltage. The reference control circuit includes an output configured to output a charge pump reference voltage based on an input power supply reference voltage before the bandgap circuit is ready, and to output the charge pump reference voltage based on the higher of the input power supply reference voltage and a bandgap reference voltage derived from the bandgap voltage after the bandgap circuit is ready. Another aspect of the present invention provides a reference control circuit. The reference control circuit provides a charge pump reference voltage to the charge pump to adjust the charge pump according to the input supply voltage to generate a pump voltage. The reference control circuit includes a first amplifier, a second amplifier, and a transistor. The first amplifier has a non-inverting input configured to receive a bandgap reference voltage, an inverting input, and an output coupled to the inverting input, wherein the bandgap reference voltage is generated from a bandgap voltage output by the bandgap circuit. The second amplifier has a non-inverting input coupled to the output of the first amplifier, an inverting input configured to receive an input power supply reference voltage generated from an input power supply voltage, and an output. The transistor has a first terminal for receiving an input supply voltage, a second terminal coupled to the output terminal of the first amplifier, and a control terminal coupled to the output terminal of the second amplifier. Drawings A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the figures, wherein like reference numbers refer to similar elements throughout the figures. FIG. 1 illustrates a booster according to one embodiment of the invention; fig. 2 shows a booster according to another embodiment of the invention; FIG. 3 illustrates waveforms of control signals according to one embodiment of the present invention; Fig. 4 shows a booster according to another embodiment of the invention; FIG. 5 illustrates waveforms of control signals according to one embodiment of the present invention; Fig. 6 shows waveforms of control signals according to another embodiment of the present invention. Detailed Description Fig. 1 shows a booster 100 according to an embodiment of the invention. The booster 100 includes a charge pump 110, a boost control circuit 120, a bandgap circuit 130, a bandgap buffer 140, a voltage divider 150, and a reference control circuit 160. In some embodiments, the booster 100 can be used for low power applications, such that low power applications can operate at low input voltages (e.g., input supply voltage VDD). In some embodiments, the input power supply voltage VDD may vary in a range between 1V and 1.4V. However, the invention is not limited thereto. In th